The invention concerns a sealing valve for container openings and consists of a cover element and a wall element formed thereon and a sealing-bead circling around the wall element, whereby the sealing-bead runs along the inside of the wall of the cap.
Sealing valves of this kind have become known in the art through Japanese patent application 58-67407.
The cells of storage batteries require a gas release valve which safely prevents the escape of battery acid and H.sub.2 gas under normal pressure conditions and, at a particular overpressure, opens within the battery cell to provide for a gas release. Since storage batteries of this type, in particular lead storage batteries for motorized vehicles, are mass-produced articles, it is necessary that their gas release valves be produced as economically as possible.
In prior battery embodiments it was customary to screw a sealing stopper, by means of a screw thread, into an opening of the cell. This stopper exhibited a small bore which facilitated a gas release of the battery cell when the sealing stopper was screwed into position. Thereby, however, battery fluid would often escape towards the outside to cause a corrosion of the sheet metal components in the vicinity of the battery.
An additional known solution consisted in the slip-fitting of a cylindrically formed sealing cap over a cylindrical gas release connector of the storage battery, the cap being made from a resilient elastic material. However, during the mass-production of these known sealing caps made from a rubber-elastic material which was necessitated for reasons of elasticity such as silicone elastomer, polyurethane (PU), and thermoplastic elastomers, unavoidably large tolerance fluctuations in the inner diameter would occur, as a result of which the production yield was disadvantageously reduced or the sealing effectivity rendered questionable. Verification of the functionability required 100% testing.
A battery stopper is known in the art from the above-mentioned Japanese patent application JP-A-59191260 with the application number 58-67407 in which a gas release connector seats over a substantial surface on the outer perimeter. Notches are provided for on the connector itself by means of which the medium under pressure interacts with the stopper.
It is the purpose of the invention to provide for a sealing valve suitable for storage batteries such that a secure gas release is achieved while simultaneously effecting a sealing with respect to the escape of battery fluids as well as an economical manufacture with increased yield.
The fundamental concept of the invention serving to achieve the above purpose consists in providing for a sealing-bead which runs around the wall element of the sealing valve, the sealing-bead exhibiting on the one hand the sealing and on the other hand the gas release function, whereby at least one control channel is provided for on the inside of a cap or a stopper, which extends from the top of the cap to the sealing-bead. By means of this sealing-bead the tolerance variations of the inner diameter during the course of mass-production are kept under control. In addition by means of the control channels which extend up to the edge of the sealing bead, the adhesive forces described above which occur between the outer wall of the gas release connector and the inner wall of the known sealing cap are prevented which had, up to this point, rendered a reliable gas release questionable. The control channels effect, for a particular overpressure inside the battery cell, an opening of the sealing valve precisely at those locations where the control channels end at the sealing-bead; in this fashion a defined release pressure of approximately 80 to 120 mbar can be adjusted.